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Shooting for the STAAR Drew Academy 2011-12 Tuesday, January 17, 2012 1. The hydra shown below is reproducing asexually. What percentage of the offspring’s genetic information is the same as the genetic information of the parent? Record your answer on grid 1. Answer 7.14B Supporting Standard 100% Organisms that reproduce asexually involve only one parent and all offspring will be genetically identical to the parent. Wednesday, January 18, 2012 A woman working out at the gym holds a 200 N weight stationary 0.7 m over her head for 10 seconds. How many of work does she do on the weight in those 10 seconds? Record your answer on grid 2. Answer TEKS 7.7A Supporting Standard The woman does no work during the ten seconds she is holding the weight over her head. Work (J) = Force (N) x distance (m) Thursday, January 19, 2012 A bicyclist travels 40 km in 2 hours. What would the total distance traveled in km if the cyclist rides for another 3 hours at the same rate? Answer TEKS 6.8C Supporting Standard 100 km If the bicyclist travels 40 km in 2 hours then the rate is 20 km per hour. If the cyclist rides for another 3 hours (a total of 5 hours) at 20 km per hour then the total distance traveled will be 100 km. Friday, January 20, 2012 The density of an object depends on two properties: the object’s mass and the object’s volume. The following equation shows how density (d) is related to mass (m) and volume (v): Density = _mass__ volume Aluminum has an average density of 2.7 g/cm3. What is the mass of a solid aluminum block with a volume of 30 cm3? Answer TEKS 6.6B Supporting Standard Using the density formula d = m/v 2.7 g/cm3 = ? / 30 cm3 m = d x v = 2.7 g/cm3 x 30 cm3 m = 81 g Tuesday, January 24, 2012 Why might you use a food web, rather than a food chain, to show how organisms in an ecosystem are related? Answer Reporting Category 1 TEKS 7.5 C Supporting Standard A food web shows that an organism can have more than one food source in an ecosystem. Wednesday, January 25, 2012 How much work in Joules is required to lift the weight vertically 1 m to the top of the ramp? Record your answer on the grid provided. Answer Reporting Category 2 TEKS 7.7 A Supporting Standard Work (Joules) = Force (Newton) x Distance (meters) The weight is to be lifted vertically; therefore, the distance moved is 1 meter. W (Joules) = 100 N x 1 m Work = 100 N • n = 100 J Thursday, January 26, 2012 Use the illustration below to explain how tides are caused. Answer Reporting Category 3 TEKS 8.7 C Supporting Standard The Moon’s gravity causes the oceans to bulge on the side of Earth closest to the Moon (label A). At the same time, gravity is also pulling Earth toward the Moon, leaving behind the ocean on the opposite side (label B). When this occurs, high tides are generated. Areas that are neither toward nor away from the Moon have low tides (labels C and D). Friday, January 27, 2012 Ecosystems are constantly being changed by the interaction of living and nonliving things. Through this constant change they remain balanced. Which example is likely to be permanent and disturb this natural balance of an ecosystem? A. In a forest, trees die and are replaced by new trees. B. A new canal is dug to control the flow of water in and out of an area. C. Seasonal changes occur in the oxygen level of water in a lake. D. Seasonal changes occur in the hydrogen level of water in a lake. Answer Report Category 4 TEKS 7.10 C Supporting Standard B